Section 329IAC10-15-8. Calculations and analyses pertaining to landfill design

   (a) The applicant shall provide calculations and analyses pertaining to the design of the proposed MSWLF unit, if applicable, and if necessary as determined by the commissioner, to indicate that the proposed design complies with the design requirements of 329 IAC 10-17. Any required calculations must be accompanied by a discussion of methods, assumptions, and the references used. Calculations that may be required include the following:

(1) A transmissivity, in plane hydraulic conductivity, calculation or an assessment based on the maximum compressive load placed above the geosynthetic, using a minimum safety factor of ten (10), when a geosynthetic material is used for the drainage layer. In addition, the long term creep impact on the transmissivity of the geosynthetic must be evaluated using a minimum safety factor of five (5).

(2) A permitivity, cross-plane hydraulic conductivity, calculation using a minimum factor of safety of fifty (50), when a geosynthetic material is used for the drainage layer.

(3) A filter-retention calculation or assessment when a geosynthetic material is used for the drainage layer.

(4) A tensile stresses calculation to evaluate stresses generated during the construction and operation of the interior of the side slope of the proposed MSWLF unit. A minimum safety factor of five (5) on yield is required.

(5) A filter-clogging calculation to evaluate the influence of retained soil particles on the permitivity of a geotextile or geonet. Also, a gradient ratio test or a hydraulic conductivity ratio test, as appropriate, must be performed in accordance with test standards specified in 329 IAC 10-17-17.

(6) A localized subsidence calculation, if applicable, to evaluate the strains induced in the geomembrane used for the liner system and for final cover.

(7) A stability of final cover calculation to evaluate the likelihood and extent to which final cover components may slide with respect to each other. A minimum safety factor as outlined in Table 1 of this section is required.

(8) A geosynthetic anchor or pull-out anchorage calculation or assessment to evaluate the anchoring capacity and stresses in a geomembrane. A minimum safety factor of one and two-tenths (1.2) is required. An anchor must provide sufficient restraint to hold a geosynthetic liner in place, but should not be so rigid or strong that the geosynthetic liner will tear before the anchor yields.

(9) A settlement potential calculation to estimate the total and differential settlement of the foundation soil due to stresses imposed by the liner system, in-place waste, daily cover, intermediate cover, equipment usage, and final cover.

(10) A bearing capacity and stability calculation to estimate the load bearing capacity and slope stability of the foundation soil during construction. A minimum safety factor of two (2.0) is required for a static condition.

(11) The uplift pressure or hydrostatic pore water pressure must be evaluated based on site-specific conditions.

(12) A waste settlement analysis to assess the potential for the final cover system to stretch due to total and differential settlement of the solid waste. If there is a lack of documented settlement of the solid waste, a value of approximately seven percent (7%) to fifteen percent (15%) of the solid waste height may be used for this calculation.

(13) A wind uplift force calculation or an assessment to provide an indication that wind uplift will not damage the geomembrane during installation.

(14) A wheel loading calculation to indicate that the amount of wheel loading of construction equipment will not damage the liner system.

(15) A puncture of geomembrane calculation to indicate that the amount of down drag force induced by the leachate collection sumps and manhole with vertical standpipe settlement will not cause failure of the underlying liner system. A minimum safety factor of two (2.0) on tensile strength at yield is required.

(16) An erosion calculation to indicate that the erosion rate will not exceed five (5) tons per acre per year, as is required under 329 IAC 10-22-7(c)(3).

(17) Pipe calculations to assess the leachate collection piping for deflection, buckling, and crushing.

(18) If applicable, or if required under 329 IAC 10-16-5(b), an analysis of the effect of seismic activity on the structural components of the landfill.

(19) A peak flow calculation to identify surface water flow expected from a twenty-five (25) year storm.

(20) A calculation to identify the total run-off volume expected to result from a twenty-five (25) year, twenty-four (24) hour precipitation event.

(21) A chemical resistance evaluation to demonstrate that the leachate collection and removal system components are chemically resistant to the waste and the leachate expected to be generated.

(22) A clogging evaluation to demonstrate that the system as designed will be resistant to clogging throughout the active life and post-closure period of the MSWLF.

(23) A slope stability analysis that follows the requirements outlined in Table 1 of this subdivision. Any geosynthetic materials installed on landfill slopes must be designed to withstand the calculated tensile forces acting upon the geosynthetic materials. The design must consider the minimum friction angle of the geosynthetic with regard to any soil-geosynthetic or geosynthetic-geosynthetic interface.

TABLE 1
Minimum Values of Safety Factors for
Slope Stability Analyses for Liner and Final Cover Systems
	Uncertainty of Strength Measurements
Consequences of Slope Failure	Small1	Large2
No imminent danger to human life or major environmental impact if slope fails	1.25 (1.2)*	1.5 (1.3)*
Imminent danger to human life or major environmental impact if slope fails	1.5 (1.3)*	2.0 or greater (1.7 or greater)*
1The uncertainty of the strength measurements is smallest when the soil conditions are uniform and high quality strength test data provide a consistent, complete, and logical picture of the strength characteristics.
2The uncertainty of the strength measurements is greatest when the soil conditions are complex and when the available strength data do not provide a consistent, complete, and logical picture of strength characteristics.
*Numbers without parentheses apply to static conditions and those within parentheses apply to seismic conditions.

(24) Any additional calculation determined by the commissioner to be necessary to ascertain whether the proposed design complies with the requirements of this article.

  (b) Test standards for MSWLF liner systems are listed in 329 IAC 10-17-17. (Solid Waste Management Division; 329 IAC 10-15-8; filed Mar 14, 1996, 5:00 p.m.: 19 IR 1825; filed Mar 19, 1998, 11:07 a.m.: 21 IR 2767; filed Aug 2, 1999, 11:50 a.m.: 22 IR 3806; filed Feb 9, 2004, 4:51 p.m.: 27 IR 1810, eff Apr 1, 2004)